This is a view of the cartridge with the top removed. It is oriented as if you had just inserted it into your player.

When you insert the tape, the capstan in the machine (a rotating steel post about 1/4" in diameter) presses against theROLLER, turning it clockwise which then pulls tape from the center of the reel.

This action also causes the HUB to rotate clockwise, which in turn takes up the "used" tape onto the outside of the reel. In this fashion, a tape will play continuously, never stopping.

This is a fine arrangement, butis mathematically impossible.

However, a few little tricks make it such that the laws of Physics can be fooled, which unfortunately means you will need to do some babysitting.

YOU DID HAVE YOURFOIL SPLICES AND PADSREPLACED OF COURSE!

The first problem:

The problem is that we are trying to remove, then replace tape - onto objects with different diameters (i.e., the inside and outside of the reel). Let's say the hub is 1.5 inches in diameter, and the outside of the reel is 2.5 inches in diameter.

Using the simple math formula for circumference (3.14 X diameter), we can then say the circumference is equal to a length of tape. So, for each revolution of the hub, we are pulling 4.71 inches of tape out, but the outside of the reel is actually pulling 7.85 inches of tape back on. And this is a short tape. If it were a bit longer, it would betaking up more than TWICE AS MUCH tape as it was giving out!

Obviously, this is impossible without doing a little head-scratching and cheating. In a very short time, the tape would be wound so tightly that it would refuse to move.

The first solution:

In order for this scheme to work, the tape needs to be able to SLIDE between layers, and also slide on the hub. This prevents the tape from binding and being woundtoo tightly. The tape is wound somewhat loosely during manufacture, and is also treated with a lubricant - usually graphite.

You'll see a silvery band on your tape rollers - this is graphite lubricant.You must always keep your tape rollers clean, and free of this lubricant !

The second problem:

As you may have guessed by now, having graphite on your rollers (and thus the capstan in your machine) is very much like going out to your car, raising the hood andpouring oil on all your drive belts. Long story short, they won't grip like they need to, and your car won't run properly for very long.

By the same token, your machine won't grip the rollers properly. This results in dragging, speed variations, or no tape movement at all. Since this is inherent in the design of the 8 track format (the only tape format that has this flaw), it is not a defect of recent repairs (especially by me!), but is rather a minor maintenance procedurethat must be performed by all owners and users of 8 track machines and tapes.

The second solution:

Basically, anything that is supposed to grip needs to be clean and free of any type of oil, grease or graphite buildup. This means keeping your tape rollers clean, as well as the capstan inside your machine. Thankfully, the capstan can be seen (and usually reached) through the tape door. Simply push that door in and peek into the back. The capstan, a vertical steel post about 1/4 inch wide, can be seen to the right of the playback head. If you have small hands, you can sometimes poke a finger through an old T shirt, dip it in household alcohol and reach it that way.

ALWAYS UNPLUG YOUR MACHINE FROM THE WALL ANY TIME YOU HAVE YOUR HANDS INSIDE IT !!!

Since you need to clean the entire capstan (not just the part that currently faces the front of the machine), you need some way to expose all sides for cleaning. One way to do this is to insert a tape and let it play a few seconds, which will hopefully expose a different area to clean. Do this several times - and with luck, you'll eventually get the entire capstan cleaned.

BE EXTREMELY CAREFUL not to disturb or break anything inside the tape door. On most models, there are some brass leaf switches that must not be bent, or other mechanical surprises that can be harmed by rough handling. If the capstan is too deep in the machine, you'll need to be a bit more creative on how to reach back there.A long stick with a small wad of cloth tied to the end, etc. Unfortunately, long Q Tips are generally not strong enough to apply any useful force - bummer!

An EXCELLENT tool to use is an 8 track tape with the roller removed, and replaced by a wad of cloth. Simply soak the wad with alcohol, pop the tape in for a minute or two, and the capstan will automatically turn against the cloth and clean itself! This will work as a routine cleaning procedure, but still will not remove years of built-upgunk or layers of tape that got sucked up by a dirty or sticky capstan. This type of repair requires a professional.

Keep in mind that TOO much alcohol will seep down onto the capstan bearings and dilute any lubricant that it needs to avoid excessive wear. So, soak the wad of cloth but not to the point that it will squeeze out and drip when put under pressure.

You also must keep the rollers on your tapes clean. You can generally do this by carefully moving the tape aside using tweezers, then use a cloth dipped in RUBBER CLEANER to clean the rollers until they are black again. Alcohol will dry out rubber, but is safe for plastic rollers. When finished, wipe off any excess rubber cleaner - it is slippery while still in liquid form. Alcohol will evaporate just fine by itself.

Hub

Tapepulledfromcenterofreel

"Used"tape istakenup ontheoutsideof thereel

Track Switch Playback Head Capstan

Roller

Capstanrotates CCW,turning rollerand hub CW

Track change switch

Playback head

Capstan

Let's open the door and look inside:

You must always keep your tape rollers clean, and free of this lubricantYou don't have to take the tapes apart to clean the rollers

Keep in mind that almost ALL 8 track tapes will need a NEW foil splice and pressurepad before they will play properly. Always check your player with a known good,RECENTLY REPAIRED tape before determining the need for professional service

NOTE: Properly maintained, 8 track machines do not eat tapes! This is caused by breakageof the foil splice on the tape itself. It is absolutely essential that any 8 track tape has a newfoil splice and pressure pad before attempting to play it. To understand why, see the yellow textbox in the upper left corner of the above illustration. We also offer quality TAPE REPAIR.